Sylvanus sawyer



y @uiten tutrs atent @ffice SYLVA'NUS SlVYll, OF- FITGHBl-HG, MASSACHUSETTS. Leiters .Patent o. 63,656, dated April' 9, i867.

IMPROVEMENT IN DIVIDERS AND GiftLIPERS.k

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'ro'nLL wHoM rrZMA'Y CONCERN: I

Bo' it known that I, SYLVANUS SAWYER, of Fitchburg, in ,thc countyof Worcester, and intho State of Massachusetts, have invented a new and useful Improvement 'in Dividers and Calipers, so that they can be adjusted with greater facility and exactness ;A and l.' do hereby deelare'that thefollowing is a full and exact description thereof, reference being had to tho accompanying drawings, and the letters of reference marked thereon; the letters of reference representing the same parts in all the figures, in which- Figures 1 and 5 represent side views of dividers and calipers respectively, they differing only in form of the legs., y l j Figure 3 is an edgewise view of the divider.

Figures 2 and'll are sectional views, showing the internal construction and arrangement of the same.

The subject-matter of my'invention consists in applying to dividers and calipers a screw-gear, in combiuap tion-with'a'stirrup, set-screw or tightener, so that when the instrument is properly adjusted, the handle as 'well as the legs can bc rigidly secured in that position, thereby preventing any displacement of the legs of the instrunient either hy the movement of the handle, vor backlash or play in the gear, which is sure to occur from the wear'of the gears o r imperfect workmanship. v

. In the drawings, A represents thehandle of the instrument carrying the screw portion of the gear, as shown at A A, dict, which has a bearing orjournal near the screw into which the stirrup or tightener fits, for purposes hereinafter described. B, the 'stock which carries the several parts thereof. C C represent the legs of the dividers or calipers, which are provided with quadrantal spiral gears,D, at their upper or joint ends, so that they can be inserted and secured in the stock B by means of the screw-pins e e', and act in conjunction with the screw and handle A, as shownmord-particularly' at D, tig.` 2, so that the points o'f the legs'shall be thrown back 4and forth simultaneously by rotating the screw-handle A. E represents the stirrup or fastener, and is'mndc of the form shown, and is provided with a holesufiioicntly large to admit oi' the passing of screw A throughit after it sha-ll have been inserted in a mor-tise provided for it inthe stock B, as shown in all the gures, and

i more particularly in iig. 4. `'lhe stirrup is also provided with a screw, which passes through the washer F, resting on stock Rand thence through a. mill-headed nut, G, so that when the nut G is screwed down upon the washer, the stirrup or I Jinder shall be drawn upA against the screw A and into a journal or hearing provided therefor, se as to conne it rigidly in-plee after the instrument has been adjusted, and also to draw it sidewiso .between and against the curves of the spiral gears in such a. manner as to wedge them, and thereby to prevent all backlash or looscness caused by Wear or imperfect workmanship, which would otherwise occur, and thereby render it inaccurate and difficult to adjust. This stirrup also, in connection with the shoulder of the journall and the mill-headed nut, serves toA keep the screw A longitudinally in place in the stock B, as shown at E,4igs. 2 and 4.

The operation of the dividers anu calipers is so simple that it hardly needs a word of explanation. The' .operator takes thc -instrument in the left hand, and after loosening the nut G he rotates the handle A so as t0 cause flic points to more to or from each other, as he may desire; or if any distance is required to be taken iu the dividers, one of the points may be set upon any given point and the handle turned, so as to bring the other point with facility and exactncss to the finest hairline. 'lhe Acalipers may be operated substantially in theA same manner. V l

There are various other mechanical devices that may be employed to reader the application of the screw or wormgear to dividers and calipers practical; as, for instance, a set-screw might be used instead of the stirrup' and set forth.

and mill-headed nut, or a bott` or ccp placed upon the bearing of thc'screw and a set-'screw forced upon it, so as to produce the same result;` or a spring `also might be employed and allowed to press upon the shank of the screw when requircthfso as to answer a similar purpose; but as allthese are mere modifications without changing the principle, I deem them immaterial. A

What I claim as my invention, and desire to secure by- Lcttcrs Patent, is

The combination of the screw or worm gear A D with the srirrup or binder E, or its equivalent, as applied to-dividcrs aud calipers, thc whoic being constructed and operating substantially in thc manner herein described SYLVANUS SAWYER. Witnesses: 4

A. Nouwr, DAVID ABRAHAM. 

